Mixing procedures and manipulations of different substances can be time consuming. In an Operation Room (OR) setting this time consumption may be critical when using a haemostatic paste for inhibiting bleedings as the surgeon will have to interrupt his procedure while waiting for the haemostat. Mixing substances from different containers may also potentially compromise the sterility of the haemostatic paste and can negatively affect the consistency of the haemostatic paste. A correct paste consistency is important for a satisfactory haemostatic effect.
Conventional haemostatic pastes are prepared at the point of use by mechanical agitation and mixing of loose powder and liquid to provide uniformity of the composition. Only after the paste is formed may the paste be placed into a delivery means or applicator, e.g. a syringe, and applied to the wound.
This procedure has been improved by for example Floseal® Haemostatic Matrix (Baxter) and Surgiflo® Haemostatic Matrix (Ethicon) where one syringe (Syringe I) is preloaded with loose gelatine powder or a pre-wetted paste, and a second syringe (Syringe II) with liquid. When it is time to make a paste, Syringes I and II are connected via a luer lock and the solution in Syringe II is pushed into Syringe I. By attempting to pass the solution and powder repeatedly back and forth between Syringes I and II, a homogeneous paste is eventually formed.
Pending PCT application WO 2014/202760 filed 20 Jun. 2014 and entitled “Vacuum expanded dry composition and syringe for retaining same” relates to a method for vacuum expansion of a paste prior to freeze-drying said paste to achieve a dry composition, which upon addition of an adequate amount of an aqueous medium, reliably and consistently reconstitutes to form a substantially homogenous and flowable paste within seconds, thereby eliminating the need for undesirable mixing requirements. This application further discloses a syringe for retaining the dry composition in a vacuum and forming the paste in the syringe after addition of the aqueous medium from an external liquid receptacle.